More than 100 witnesses have testified about a series of retaliatory shootings that culminated in a massacre on South Capitol Street -- and the outcome of the case might turn on their credibility.

Attorneys for the five men charged in the March 2010 shootings that left five dead and nine wounded sought to cast doubt on the reliability of those witnesses in their closing arguments Monday.

Witnesses who testified about Sanquan Carter's alleged role in a shooting prompted by his anger over a missing bracelet were drunk or on drugs during the event, defense attorney Arthur Ago said. The witnesses told prosecutors what they wanted to hear so the witnesses could get plea agreements in their own cases, Ago said.

"His motive is to help himself, not tell the truth," Ago said of Andre Morgan, the only person to hear Carter allegedly tell his brother, Orlando, and friends to bring weapons to the party. Morgan faced charges from a retaliatory shooting of Orlando Carter and other offenses and reached a plea deal, Ago said.

Ago said Carter only fired a weapon to defend himself.

When he saw someone reaching for what Carter thought was a firearm, "he shot in self-defense," Ago said. Ago said his client was friends with 20-year-old Jordan Howe, the man killed that night, and never conspired to harm Howe or anyone else.

"There was no intent whatsoever," he said.

But the slaying on the 1300 block of Alabama Avenue sparked Morgan and others to shoot Orlando Carter the next day, authorities say. A week later, Orlando Carter, Jeffrey Best, Robert Bost and Nathaniel Simms allegedly piled into a minivan and opened fire on a crowd of mourners from Howe's funeral gathered on the 4000 block of South Capitol Street. In both the Alabama Avenue and South Capitol Street shootings, prosecutors say, they used guns supplied by Lamar Williams.

Simms has pleaded guilty and is cooperating with prosecutors. The other five men have been on trial in D.C. Superior Court since February.

In the final part of his closing argument, prosecutor Bruce Hegyi tried to convince the jury that DNA, cellphone records and other evidence corroborates testimony from Simms and other witnesses, whose statements also support each other.

Hegyi also tried to dispel any idea that any of the shootings were anything but premeditated.

When the group was getting guns from Williams, he said, "They were getting ready to go. There was no doubt about what they intended to do."