Jovan Belcher appeared to have it all.

On Sundays, he pulled his No. 59 Kansas City Chiefs jersey over his shoulder pads and played in the National Football League, the elusive dream of thousands of young players.

Belcher had been a barely recruited high school football player in West Babylon, N.Y., only to blossom into an All-American at the University of Maine, where he gained the attention of NFL scouts.

Things are not always what they seem on the surface.

Belcher’s success story ended abruptly Saturday morning in Kansas City when he shot and killed his girlfriend, Kasandra Perkins, at their home, then drove to the Chiefs’ practice facility and committed suicide in front of some team personnel.

The couple leaves behind a 3-month-old daughter, Zoe.

Former teammates and coaches of the fourth-year NFL linebacker were left dazed and unable to come to terms with how the Jovan Belcher they knew could have committed such heinous acts.

What, they wondered, sent Belcher off the deep end?

Apparently, Belcher was experiencing some serious issues in his personal life, including increasing relationship problems with Perkins.

An unidentified friend of Belcher is quoted on the website Deadspin as saying Belcher not only was experiencing issues resulting from head injuries, but was using alcohol daily and was taking prescription drugs for pain relief. Deadspin is a sports website owned by Gawker Media.

Belcher sat out the Chiefs’ Nov. 25 game, presumably because of a head injury he suffered during a Nov. 18 game against Cincinnati.

The friend reported Belcher was “dazed and suffering from short-term memory loss” after the Nov. 18 game, during which he said the player received some direct hits to the head.

The website cited the source’s detailed knowledge of Belcher’s behavior and personal life in using his unattributed comments. The person told Deadspin he was concerned the media were concentrating on only a few elements of the story.

The extent of any concussions or head injuries during Belcher’s three-plus seasons in Kansas City has not been made public in detail, although Chiefs chairman Clark Hunt told ABC News that Belcher was “a player who had not had a long concussion history.”

Belcher does not appear to have had any prior reported history of domestic violence.

A review of the Bangor Daily News’ story archives did not produce any evidence that Belcher had been in trouble with the law during his four years attending UMaine. Representatives of the Orono and UMaine police departments said Saturday that Belcher had not been charged with any crimes during his time at the university.

While in Orono, Belcher belonged to the Male Athletes Against Violence student group. He seemed sincere in his participation, according to former teammate Mike Brusko, another member.

The alleged off-field problems seem to be reinforced in the fact Belcher, at some point, procured a handgun. The weapon was subsequently used in Saturday’s murder-suicide.

With Belcher gone, we will never know the true depth of his personal struggles or his mental state leading up to the tragedy.

There is only one remaining piece of the puzzle that might shed some light on the situation.

There has been increasing discussion in recent years about the frequency of concussions incurred by athletes, especially those who play in the NFL.

Belcher did not appear to have had any concussions while playing for the Black Bears, although UMaine does not release such medical information, citing federal privacy laws.

Even if he did not have a longstanding history of concussions, perhaps the most recent brain injury, coupled with stress and possible substance use, could have contributed to what transpired on Saturday.

High-profile cases of other NFL players has helped fuel considerable scientific study about what effect concussions and repeated blows to the head — even one protected by a helmet — have on an individual’s ability to think clearly and make decisions.

Belcher’s suicide comes after former All-Pro linebacker Junior Seau and NFL retiree Dave Duerson both took their own lives with a firearm in the last two years. Neither of them injured anyone else in the course of their actions.

Such incidents have further fueled speculation about brain injuries and how they might affect the players’ thought process and his behavior. In fact, the brains of both men are being studied at Boston University’s Center for the Study of Traumatic Encephalopathy.

It may never be known what caused Belcher to take such extreme and irreversible actions, but perhaps toxicology reports and study of his brain tissue can shed some light on why he took two lives on Saturday.

Pete graduated from Bangor High School in 1980 and earned a B.S. in Journalism (Advertising) from the University of Maine in 1986. He grew up fishing at his family's camp on Sebago Lake but didn't take...