WASHINGTON (Reuters) - A Maryland man suspected of shooting dead a firefighter and wounding another in April has been indicted on weapons charges, a prosecutor said on Thursday.

The suspect, Darrell Lumpkin, of Temple Hills, said he shot the men in suburban Washington because he thought they were breaking into his home, authorities have said.

"This is a tragedy that none of us expected," Prince George's County State's Attorney Angela Alsobrooks told reporters.

Lumpkin is suspecting of killing John Ulmschneider, 37, a firefighter and medic, and wounding Kevin Swain, 19, a volunteer firefighter. The firefighters had been asked to check on Lumpkin's welfare and tried to force the door open when there was no response to their knocks.

Lumpkin's brother was also wounded.

A grand jury indicted Lumpkin on six counts of possessing a firearm after being convicted of a crime of violence in the District of Columbia.

(Reporting by Ian Simpson; Editing by Leslie Adler)