While teaching German at Harvard University he poisoned his pregnant wife. He fled before this was discovered, and spent the next decade in various places in the United States under assumed identities.
On July 2, 1915, Muenter hid a package containing three sticks of dynamite with a timing mechanism set for nearly midnight under a telephone switchboard in the Senate reception room in the United States Capitol, Washington, D.C. His original target had been the Senate chamber, which he found locked. The bomb exploded at approximately 11:40 PM resulting in no casualties. Muenter wrote a letter to The Washington Star under a pseudonym, explaining his actions. which was published after the bombing. He said that he hoped the explosion would "make enough noise to be heard above the voices that clamor for war. This explosion is an exclamation point in my appeal for peace."
After setting off the bomb in the Capitol, he fled to New York City, where he hid a time bomb on SS Minnehaha, a ship loaded with munitions bound for Britain. He then made his way to the home of financier J. P. Morgan, Jr. in Glen Cove, New York. Morgan had arranged for Britain to borrow large amounts in the US to finance its war effort against Germany, which angered Muenter. Muenter shot Morgan twice in the groin, but failed to kill him and was captured. (One source says that Morgan's butler subdued Muenter with a chunk of coal.)
He was charged with both crimes and soon after committed suicide in jail. On July 7, just two days after his jail cell suicide, the bomb he had planted on Minnehaha exploded. It had been placed far away from the munitions, and the resulting fire only caused minor damage.
- "Chas. Apted Dies; 'Cop' at Harvard". New York Times. June 6, 1941. p. 21.
- Russell, Daniel E. "The Day Morgan Was Shot" (PDF). Glen Cove Heritage.[better source needed]
- "Man Who Shot J. P. Morgan Twice Admits Setting Bomb At National Capital". Hartford Courant. July 4, 1915. Retrieved 2009-10-30.
Former German Instructor At Cornell Talks Freely After Third Degree Is Used, and Says He Wanted To Stop Shipment of Munitions To Europe. Is Suspected of Other, Similar Crimes. Describes Construction of Rare Type of 'Infernal Machine'. Financier Reported in Excellent Condition. Has Two Bullet Wounds In His Hip.
- "Bomb Rocks Capitol". United States Senate. Retrieved 19 May 2013.
- Kinghorn, Jonathan. "S.S. Minnehaha". The Atlantic Transport Line. Retrieved 14 June 2014.